Nd:YAG热疗对小鼠S_(180)肉瘤的抑制作用

The Inhibiting Effect of Hyperthermia by Nd: YAG Laser Radiation on Transplanted Tumor in Mice

目的：研究Nd：YAG激光热疗会对小鼠S180肉瘤作用的剂量选择、作用效果及对肿瘤DNA含量影响。方法：荷瘤小鼠分为激光热疗组和对照组，激光热疗法用Nd：YAG激光照射肿瘤，功率密度约为424mW／cm2，控制肿瘤边缘温度为43℃，照射时间为30min；24小时后测量肿瘤细胞的DNA含量，5天后测量肿瘤的抑制率。结果：两组肿瘤的平均瘤重差异有显著性（P＜0.01），激光热疗组肿瘤抑制率为31．8％，激光热疗组肿瘤细胞的DNA含量比对照组低（P＜0．01）。结论：在所选定的激光剂量下，Nd：YAG激光热疗对小鼠S180肉瘤确有抑制作用，肿瘤细胞DNA含量的降低可能是Nd：YAG激光热疗对肿瘤抑制作用的途径之一，Nd：YAG热疗法值得进一步深入研究。

Objective: To study the dose select and the inhibiting effect of hyperthermia induced by Nd:YAG laser on the transplanted sarcoma 180 in mice. Methods: Tumor - bearing mice were divided into control group and hyperthermia group. Tumor - bearing mice of hyperthermia group were given Nd: YAG luser radiation and the temperature in tumor edge was controled at 43℃ (about 424mW/cm2) for 30 minutes. The DNA contant of tumor cell were also measured with microspectrophotometry 24 hours after laser radiation.The tumor inhibition rates were deteimined 5 dsys after treatment. Results: The experments showed the average tumor weight of hyperthermia group had significant differecces compared with that of control group (P < 0.01). The trmor inhibitory rates of hyperthermia group was 31. 8%. The DNA content showed very significant decrease after Nd: YAG laser radiation (P < 0.01). Conclusion: The inhibiting effect of hyperthermia by Nd:YAG laser were indentified at the selected laser dose. The decreasing of DNA content of tumor cell after Nd:YAG radiation may be one of the reasons of the inhibiting effect of hyperthermia by Nd:YAG laser. It is recommonded that the method be studied further based on the expeerimental results.